![]() It turns out that already these effects are related to response requirements because effects of stimulus frequency actually are effects of frequency of response‐defined stimulus categories and effects of relevance may be defined as effects of graduating the response requirements. The present review first focusses on effects of the classic variables stimulus frequency and relevance on P3b amplitude. This has changed in the recent decade when P3b has been related to aspects of the decision process. Traditionally, hypotheses on P3b have conceived of this component being independent from implementing the response to the present stimulus. This network may underlie activation of the S-R links, thus possibly also the P3b component, forming a bridging step between sensory encoding and response execution.ĭiverse psychological correlates have been ascribed to “P300,” the conspicuous P3b component of event‐related potentials (ERPs) recorded in many laboratory tasks. The obtained fMRI results showed that processing of the relevant S1 involved activation of a distributed postero-anterior sensorimotor network, and increased strength of functional connectivity within this network. The obtained EEG results suggest that P3b may be interpreted in terms of the S-R link activation account, although further studies are needed to disentangle P3-related activity from overlapping anticipatory activity. In both experiments, two successive visual stimuli, S1 and S2, were presented with a 1 sec interval, and responses were defined either by S1 or S2, while participants responded only after S2 onset. Here, we conducted an EEG experiment examining whether P3b may indeed reflect an S-R link activation, followed by an fMRI experiment in which we explored the brain areas and functional connectivity possibly constituting the neural basis of these sensorimotor links. One of the main issues is whether P3b reflects only stimulus-related processes (stimulus evaluation hypothesis) or response-related processes as well (stimulus-response or S-R link activation hypothesis). The functional meaning and neural basis of the P3b component of ERPs are still under debate. Results suggest that the aI is involved in voluntary attentional processing of task-relevant information, whereas the pI is involved in automatic auditory processing. Auditory target detection was associated with P300 ERPs, and alpha, theta, high- and low-gamma responses, preferentially at aI contacts. N100 responses to auditory stimuli were mostly observed in the pI and were little affected by task conditions. Event-related potentials (ERPs) were analyzed using permutation analyses during the N100 and the P300 intervals, and modulations of alpha, theta, and gamma band responses were compared using Wilcoxon/Mann–Whitney analyses. ![]() Recordings were obtained from depth electrodes implanted in 11 insulae. Eight epileptic patients completed two passive listening tasks and one three-stimulus auditory oddball detection task during the intracranial EEG monitoring of their drug-resistant seizures. Our study examines the spatiotemporal dynamics of auditory processing in the insula using intracranial electroencephalography (EEG). As the anterior insula (aI) and the posterior insula (pI) have different connections and are thought to be functionally distinct, it is likely that these two areas contribute differently to auditory processing. However, due to the limited temporal resolution of non-invasive neuroimaging techniques, the role(s) of the insula in auditory processing remains unclear. Functional neuroimaging studies using auditory stimuli consistently show activation of the insular cortex. ![]()
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